US drones have continued thier missile attacks in the Federally administered tribal areas of north-west Pakistan killing six people and injuring several others in the recent strike in South Waziristan on Tuesday.According to sources, US unmanned drone planes fired three hellfire missiles in Ladha tehsil of South Waziristan which hit a house killing at least six people and wounding several others.Tehsil Ladha is considered a stronghold of the militant commander,Baitullah Mehsod and massive operation is underway against him in the area. An other strong commander,Qari Zainudin, who stood against Baitullah Mehsod, was also killed earlier. Qari Zainudin has said he is not in favour of attacks against the Pakistan government.